
<template>
 <div class="sidebar">
        <el-menu class="sidebar-el-menu" :default-active="onRoutes" :collapse="collapse" background-color="#324157"
         text-color="#bfcbd9" active-text-color="#20a0ff" unique-opened router>
           <template v-for="item in items">
                <template v-if="item.subs">
                     <el-submenu :index="item.index" :key="item.index">
                           <template slot="title">
                            <i :class="item.icon"></i><span slot="title">{{ item.title }}</span>
                        </template>
                          <template v-for="subItem in item.subs">
                            <el-submenu v-if="subItem.subs" :index="subItem.index" :key="subItem.index">
                                <template slot="title">{{ subItem.title }}</template>
                                <el-menu-item v-for="(threeItem,i) in subItem.subs" :key="i" :index="threeItem.index">
                                    {{ threeItem.title }}
                                </el-menu-item>
                            </el-submenu>
                            <el-menu-item v-else :index="subItem.index" :key="subItem.index">
                                {{ subItem.title }}
                            </el-menu-item>
                        </template>
                     </el-submenu>
                </template>
                  <template v-else>
                    <el-menu-item :index="item.index" :key="item.index">
                        <i :class="item.icon"></i><span slot="title">{{ item.title }}</span>
                    </el-menu-item>
                </template>
           </template>

        </el-menu>
 </div>
</template>


<script>
import bus from "../vuex/bus";

export default {
  data() {
    return {
      collapse: true,
      items: [
        {
          icon: "el-icon-setting",
          index: "home",
          title: "系统首页"
        },
        {
          icon: "el-icon-tickets",
          index: "admin",
          title: "管理"
        },
        {
          icon: "el-icon-message",
          index: "menu",
          title: "菜单"
        },
        {
          icon: "el-icon-news",
          index: "Tabs",
          title: "Tabs页面"
        },
        {
          icon: "el-icon-date",
          index: "3",
          title: "关于我们",
          subs: [
            {
              index: "history",
              title: "历史订单"
            },
            {
              index: "3-2",
              title: "联系我们",
              subs: [
                {
                  index: "phone",
                  title: "电话号码"
                },
                {
                  index: "phoneName",
                  title: "姓名"
                }
              ]
            },
            {
              index: "orderingGuide",
              title: "点餐文档"
            }
          ]
        }
      ]
    };
  },
  computed: {
    onRoutes() {
      return this.$route.path.replace("/", "");
    }
  },
  created() {
    // 通过 Event Bus 进行组件间通信，来折叠侧边栏
    bus.$on("collapse", msg => {
      this.collapse = msg;
    });
  }
};
</script>

<style scoped>
.sidebar {
  display: block;
  position: absolute;
  left: 0;
  top: 0px;
  bottom: 0;
  overflow-y: scroll;
  min-height: 100%;
}
.sidebar::-webkit-scrollbar {
  width: 0;
}
.sidebar-el-menu:not(.el-menu--collapse) {
  width: 250px;
}
.sidebar > ul {
  min-height: 100%;
}
</style>